The 3rd generation mobile communication system has been applied commercially around the world. With the increase of users, traffic is increasing, and users raise higher requirements on quality of service provided by the 3rd generation mobile communication network. In existing mobile services, obstacles such as indoor walls lead to signal loss, and indoor signals of user equipment (user equipment, User's Equipment) are of low quality, which reduces user communication quality.
To solve these problems, a Femtocell (Femtocell) base station technology is introduced. A Femtocell base station is set at a user's home, which saves operation costs of equipment room, power supply, air conditioners, and circuit maintenance and provides good indoor coverage. The Femtocell base station has a small coverage radius, and terminals connected to it decrease its transmit power, which saves batteries and reduces radiation to the human body. However, introducing many Femtocell base stations brings new problems to existing macro cells, for example, interference caused by signals transmitted by the Femtocell base station onto the macro cells, and handover between a macro cell and a cell that covers the Femtocell base station. To reduce the interference caused by the signals transmitted by the Femtocell base station onto the macro cell, most networking schemes in the prior art recommend inter-frequency networking of Femtocell and macro networks. However, inter-frequency networking may make user equipment in an area with good macro cell signals unable to reselect a Femtocell. If the user equipment is forced to search for inter-frequency neighboring cells, it will make the user equipment consume too much power. Moreover, to implement reselection from a macro cell to a Femtocell, a cell generated by signals transmitted by multiple different Femtocell base stations needs to be configured to each macro cell as its neighboring cell. Such factors become big bottlenecks of deploying Femtocell base stations massively.
Specifically, in the prior art, a pseudo pilot technology may be used, which guides the user equipment to hand over from a macro cell to a Femtocell. Specifically, it is assumed that base station A is a macro cell base station and base station B is a Femtocell base station, and a mobile station roams to base station A and uses carrier F2 for communication. When the mobile station is gradually away from base station A and closer to base station B, base station B has only carrier F1 that is available. The F2 signals received by the mobile station from base station A are weaker and weaker, but the F1 signals of base station B are stronger and stronger. Meanwhile, base station B transmits pseudo pilots on carrier F2. The pseudo pilots have only energy, but never provide traffic channels. That is, the pseudo pilots cannot be parsed. When the mobile station is served by base station A of carrier F2 and moves from base station A to base station B, the mobile station keeps detecting pilot signal strength of nearby base stations. When the value of a pilot adding threshold (T_ADD) parameter exceeds a threshold, the mobile station sends a pilot strength measuring message (PSMM, Pilot Strength Measuring Message) to base station A proactively. After receiving the message, base station A queries configuration information of neighboring base stations, and finds that pilot signals of F2 of base station B are actually pseudo pilot signals. The pseudo pilot signals are interfering signals that cannot be parsed, but F1 of base station B can provide service channels. Base station A sends an extended handoff direction message (EHDM, Extended Hand-off Direction Message) to the mobile station, whereby the mobile station is instructed to hand over to carrier F1 and handover parameters are sent to the mobile station. The mobile station promptly hands over to carrier F1 of base station A, and then hands over from carrier F1 of base station A to carrier F1 of base station B in a soft handover manner, thereby ensuring smooth handover.
In the process of researching and practicing the prior art, the inventors of the present invention find that in the method for reselecting a cell according to the pseudo pilot, the signals transmitted by base station B and including pseudo pilots generate co-channel interference onto the cell formed by coverage of base station A. The signals that transmit pseudo pilots are very strong, and the pseudo pilots are not capable of providing services, but carry noise signals of enormous energy, which makes the user equipment initiate inter-frequency measurement. Therefore, in the prior art, the co-channel interference increases, which deteriorates the communication environment of the cell and affects the users who use services normally in the cell. Meanwhile, the electric quantity consumed by inter-frequency measurement initiated by the user equipment increases, which increases the user equipment's radiation onto the human body.
Further, much information on Femtocells (base station Bs given above as examples) adjacent to the macro cell, such as pseudo pilot signals transmitted by neighboring Femtocell base stations and pilots capable of providing services in the neighboring Femtocells, needs to be configured in base station A in the macro cell. Such information imposes heavier base station configuration loads in the macro cell and hinders base station equipment management in the macro cell.